As long as it sits on the shelf, its potential energy
relative to the floor is . . .
Potential energy = (mass) x (gravity) x (height) =
(3 kg) x (9.8 m/s²) x (0.8m) = <u>23.52 joules</u> .
If it falls from the shelf and lands on the floor, then it has exactly that
same amount of energy when it hits the floor, only now the 23.52 joules
has changed to kinetic energy.
Kinetic energy = (1/2) x (mass) x (speed)²
23.52 joules = (1/2) x (3 kg) x (speed)²
Divide each side by 1.5 kg : 23.52 m²/s² = speed²
Take the square root of each side: speed = √(23.52 m²/s²) = <em>4.85 m/s </em> (rounded)
Weight of an object is given by the formula W = m x g , where
m : mass of the object
g : gravitational acceleration
It is <u>independent of the horizontal </u><u>acceleration</u>.
<h3>What do we mean by weight of an object?</h3>
Weight is a gauge of how strongly gravity is<u> pulling something down.</u> It is dependent on the object's mass, or how much matter it consists of. It also depends on the <u>object's uniformly distributed</u> downward acceleration caused by gravity.
This equation can be used to express weight:
W = m x g
<h3>What is the difference between weight and mass of an object?</h3>
In everyday speech, the phrases "mass" and "weight" are frequently used interchangeably; nevertheless, the two concepts don't have the same meaning. In contrast to weight, which is a <u>measurement of</u> how the <u>force</u> of gravity works upon a mass, mass is the <u>amount of substance</u> in a material.
To learn more about gravity and acceleration :
brainly.com/question/13860566
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Iron is a magnetic metal, and it is essential to the Earth's magnetic field!
Essentially it "records" (stores the information, maintains) the direction and orientation of the magnetic field.
Among others, the magnetic field protects the Earth from dangerous cosmic rays.